import {onUnmounted, ref,computed} from 'vue'
import dayjs from 'dayjs'
export const useCountDown = ()=>{
    let timer = null
    let time = ref(0)
    // 格式化时间 为 xx分xx秒
    const formatTime = computed(() => dayjs.unix(time.value).format('mm分ss秒'))
    const start = (currentTime)=>{
        time.value = currentTime
        timer = setInterval(()=>{
            time.value--
        },1000)
    }
    // 组件销毁时清除定时器
    onUnmounted(()=>{
        console.log('xiaobb');
        timer && clearInterval(timer)//如果存在就消除
    })
    return{
        formatTime,
        start
    }
}